According to my shell client, the install "failed with error". But the terminal output looks ok. Does it look like this install failed?
Loading composer repositories with package information Updating dependencies Package operations: 2 installs, 0 updates, 0 removals - Installing elasticsearch/elasticsearch (5.3.0): Downloading (connecting...)Downloading (0%) Downloading (5%)Downloading (10%)Downloading (15%)Downloading (20%)Downloading (25%)Downloading (30%)Downloading (35%)Downloading (40%)Downloading (45%)Downloading (50%)Downloading (55%)Downloading (60%)Downloading (65%)Downloading (70%)Downloading (75%)Downloading (80%)Downloading (85%)Downloading (90%)Downloading (95%)Downloading (100%) - Installing ruflin/elastica (5.3.0): Downloading (connecting...)Downloading (100%) Writing lock file Generating autoload files